Wavelength switch systems (WSS) currently require passive optical components to tap the optical power from their fibers and feed these tapped signals to a monitoring system. The tapped signals are used to provide a feedback signal to control the WSS. Generally, there are two approaches to obtaining these feedback signals. The first approach includes an external optical channel monitoring (OCM) system that operates nearly independently of the WSS. A servo system responsive to external electronics controls the micromirrors of the WSS and serves the function of integrating the WSS and the OCM. A second approach is to build an OCM that feeds its output signals directly to the electronics that control the WSS. The advantage of this approach is that the servo algorithm becomes part of the system design, the stability of the overall system can be optimized, and the integration of electronics saves costs. The benefits of an optical integration have not been previously realized because of the difficulty in achieving the same performance and stability in the above approaches through the use of passive components in a free-space optics system without significantly increasing the cost.
Thus, there is a need in the art, for optical integration of passive components with improved performance while reducing both size and cost.